EDAC, mellanox: Add ECC support for BlueField DDR4
authorShravan Kumar Ramani <sramani@mellanox.com>
Tue, 25 Jun 2019 19:13:59 +0000 (15:13 -0400)
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Thu, 8 Aug 2019 15:57:01 +0000 (12:57 -0300)
Add ECC support for Mellanox BlueField SoC DDR controller.
This requires SMC to the running Arm Trusted Firmware to report
what is the current memory configuration.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Shravan Kumar Ramani <sramani@mellanox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
MAINTAINERS
drivers/edac/Kconfig
drivers/edac/Makefile
drivers/edac/bluefield_edac.c [new file with mode: 0644]

index 7c22905..97912d8 100644 (file)
@@ -5757,6 +5757,11 @@ S:       Supported
 F:     drivers/edac/aspeed_edac.c
 F:     Documentation/devicetree/bindings/edac/aspeed-sdram-edac.txt
 
+EDAC-BLUEFIELD
+M:     Shravan Kumar Ramani <sramani@mellanox.com>
+S:     Supported
+F:     drivers/edac/bluefield_edac.c
+
 EDAC-CALXEDA
 M:     Robert Richter <rric@kernel.org>
 L:     linux-edac@vger.kernel.org
index 200c04c..2a2603b 100644 (file)
@@ -510,4 +510,11 @@ config EDAC_ASPEED
          First, ECC must be configured in the bootloader. Then, this driver
          will expose error counters via the EDAC kernel framework.
 
+config EDAC_BLUEFIELD
+       tristate "Mellanox BlueField Memory ECC"
+       depends on ARM64 && ((MELLANOX_PLATFORM && ACPI) || COMPILE_TEST)
+       help
+         Support for error detection and correction on the
+         Mellanox BlueField SoCs.
+
 endif # EDAC
index 165ca65..d265ff9 100644 (file)
@@ -85,3 +85,4 @@ obj-$(CONFIG_EDAC_XGENE)              += xgene_edac.o
 obj-$(CONFIG_EDAC_TI)                  += ti_edac.o
 obj-$(CONFIG_EDAC_QCOM)                        += qcom_edac.o
 obj-$(CONFIG_EDAC_ASPEED)              += aspeed_edac.o
+obj-$(CONFIG_EDAC_BLUEFIELD)           += bluefield_edac.o
diff --git a/drivers/edac/bluefield_edac.c b/drivers/edac/bluefield_edac.c
new file mode 100644 (file)
index 0000000..e4736eb
--- /dev/null
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Bluefield-specific EDAC driver.
+ *
+ * Copyright (c) 2019 Mellanox Technologies.
+ */
+
+#include <linux/acpi.h>
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/edac.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "edac_module.h"
+
+#define DRIVER_NAME            "bluefield-edac"
+
+/*
+ * Mellanox BlueField EMI (External Memory Interface) register definitions.
+ */
+
+#define MLXBF_ECC_CNT 0x340
+#define MLXBF_ECC_CNT__SERR_CNT GENMASK(15, 0)
+#define MLXBF_ECC_CNT__DERR_CNT GENMASK(31, 16)
+
+#define MLXBF_ECC_ERR 0x348
+#define MLXBF_ECC_ERR__SECC BIT(0)
+#define MLXBF_ECC_ERR__DECC BIT(16)
+
+#define MLXBF_ECC_LATCH_SEL 0x354
+#define MLXBF_ECC_LATCH_SEL__START BIT(24)
+
+#define MLXBF_ERR_ADDR_0 0x358
+
+#define MLXBF_ERR_ADDR_1 0x37c
+
+#define MLXBF_SYNDROM 0x35c
+#define MLXBF_SYNDROM__DERR BIT(0)
+#define MLXBF_SYNDROM__SERR BIT(1)
+#define MLXBF_SYNDROM__SYN GENMASK(25, 16)
+
+#define MLXBF_ADD_INFO 0x364
+#define MLXBF_ADD_INFO__ERR_PRANK GENMASK(9, 8)
+
+#define MLXBF_EDAC_MAX_DIMM_PER_MC     2
+#define MLXBF_EDAC_ERROR_GRAIN         8
+
+/*
+ * Request MLNX_SIP_GET_DIMM_INFO
+ *
+ * Retrieve information about DIMM on a certain slot.
+ *
+ * Call register usage:
+ * a0: MLNX_SIP_GET_DIMM_INFO
+ * a1: (Memory controller index) << 16 | (Dimm index in memory controller)
+ * a2-7: not used.
+ *
+ * Return status:
+ * a0: MLXBF_DIMM_INFO defined below describing the DIMM.
+ * a1-3: not used.
+ */
+#define MLNX_SIP_GET_DIMM_INFO         0x82000008
+
+/* Format for the SMC response about the memory information */
+#define MLXBF_DIMM_INFO__SIZE_GB GENMASK_ULL(15, 0)
+#define MLXBF_DIMM_INFO__IS_RDIMM BIT(16)
+#define MLXBF_DIMM_INFO__IS_LRDIMM BIT(17)
+#define MLXBF_DIMM_INFO__IS_NVDIMM BIT(18)
+#define MLXBF_DIMM_INFO__RANKS GENMASK_ULL(23, 21)
+#define MLXBF_DIMM_INFO__PACKAGE_X GENMASK_ULL(31, 24)
+
+struct bluefield_edac_priv {
+       int dimm_ranks[MLXBF_EDAC_MAX_DIMM_PER_MC];
+       void __iomem *emi_base;
+       int dimm_per_mc;
+};
+
+static u64 smc_call1(u64 smc_op, u64 smc_arg)
+{
+       struct arm_smccc_res res;
+
+       arm_smccc_smc(smc_op, smc_arg, 0, 0, 0, 0, 0, 0, &res);
+
+       return res.a0;
+}
+
+/*
+ * Gather the ECC information from the External Memory Interface registers
+ * and report it to the edac handler.
+ */
+static void bluefield_gather_report_ecc(struct mem_ctl_info *mci,
+                                       int error_cnt,
+                                       int is_single_ecc)
+{
+       struct bluefield_edac_priv *priv = mci->pvt_info;
+       u32 dram_additional_info, err_prank, edea0, edea1;
+       u32 ecc_latch_select, dram_syndrom, serr, derr, syndrom;
+       enum hw_event_mc_err_type ecc_type;
+       u64 ecc_dimm_addr;
+       int ecc_dimm;
+
+       ecc_type = is_single_ecc ? HW_EVENT_ERR_CORRECTED :
+                                  HW_EVENT_ERR_UNCORRECTED;
+
+       /*
+        * Tell the External Memory Interface to populate the relevant
+        * registers with information about the last ECC error occurrence.
+        */
+       ecc_latch_select = MLXBF_ECC_LATCH_SEL__START;
+       writel(ecc_latch_select, priv->emi_base + MLXBF_ECC_LATCH_SEL);
+
+       /*
+        * Verify that the ECC reported info in the registers is of the
+        * same type as the one asked to report. If not, just report the
+        * error without the detailed information.
+        */
+       dram_syndrom = readl(priv->emi_base + MLXBF_SYNDROM);
+       serr = FIELD_GET(MLXBF_SYNDROM__SERR, dram_syndrom);
+       derr = FIELD_GET(MLXBF_SYNDROM__DERR, dram_syndrom);
+       syndrom = FIELD_GET(MLXBF_SYNDROM__SYN, dram_syndrom);
+
+       if ((is_single_ecc && !serr) || (!is_single_ecc && !derr)) {
+               edac_mc_handle_error(ecc_type, mci, error_cnt, 0, 0, 0,
+                                    0, 0, -1, mci->ctl_name, "");
+               return;
+       }
+
+       dram_additional_info = readl(priv->emi_base + MLXBF_ADD_INFO);
+       err_prank = FIELD_GET(MLXBF_ADD_INFO__ERR_PRANK, dram_additional_info);
+
+       ecc_dimm = (err_prank >= 2 && priv->dimm_ranks[0] <= 2) ? 1 : 0;
+
+       edea0 = readl(priv->emi_base + MLXBF_ERR_ADDR_0);
+       edea1 = readl(priv->emi_base + MLXBF_ERR_ADDR_1);
+
+       ecc_dimm_addr = ((u64)edea1 << 32) | edea0;
+
+       edac_mc_handle_error(ecc_type, mci, error_cnt,
+                            PFN_DOWN(ecc_dimm_addr),
+                            offset_in_page(ecc_dimm_addr),
+                            syndrom, ecc_dimm, 0, 0, mci->ctl_name, "");
+}
+
+static void bluefield_edac_check(struct mem_ctl_info *mci)
+{
+       struct bluefield_edac_priv *priv = mci->pvt_info;
+       u32 ecc_count, single_error_count, double_error_count, ecc_error = 0;
+
+       /*
+        * The memory controller might not be initialized by the firmware
+        * when there isn't memory, which may lead to bad register readings.
+        */
+       if (mci->edac_cap == EDAC_FLAG_NONE)
+               return;
+
+       ecc_count = readl(priv->emi_base + MLXBF_ECC_CNT);
+       single_error_count = FIELD_GET(MLXBF_ECC_CNT__SERR_CNT, ecc_count);
+       double_error_count = FIELD_GET(MLXBF_ECC_CNT__DERR_CNT, ecc_count);
+
+       if (single_error_count) {
+               ecc_error |= MLXBF_ECC_ERR__SECC;
+
+               bluefield_gather_report_ecc(mci, single_error_count, 1);
+       }
+
+       if (double_error_count) {
+               ecc_error |= MLXBF_ECC_ERR__DECC;
+
+               bluefield_gather_report_ecc(mci, double_error_count, 0);
+       }
+
+       /* Write to clear reported errors. */
+       if (ecc_count)
+               writel(ecc_error, priv->emi_base + MLXBF_ECC_ERR);
+}
+
+/* Initialize the DIMMs information for the given memory controller. */
+static void bluefield_edac_init_dimms(struct mem_ctl_info *mci)
+{
+       struct bluefield_edac_priv *priv = mci->pvt_info;
+       int mem_ctrl_idx = mci->mc_idx;
+       struct dimm_info *dimm;
+       u64 smc_info, smc_arg;
+       int is_empty = 1, i;
+
+       for (i = 0; i < priv->dimm_per_mc; i++) {
+               dimm = mci->dimms[i];
+
+               smc_arg = mem_ctrl_idx << 16 | i;
+               smc_info = smc_call1(MLNX_SIP_GET_DIMM_INFO, smc_arg);
+
+               if (!FIELD_GET(MLXBF_DIMM_INFO__SIZE_GB, smc_info)) {
+                       dimm->mtype = MEM_EMPTY;
+                       continue;
+               }
+
+               is_empty = 0;
+
+               dimm->edac_mode = EDAC_SECDED;
+
+               if (FIELD_GET(MLXBF_DIMM_INFO__IS_NVDIMM, smc_info))
+                       dimm->mtype = MEM_NVDIMM;
+               else if (FIELD_GET(MLXBF_DIMM_INFO__IS_LRDIMM, smc_info))
+                       dimm->mtype = MEM_LRDDR4;
+               else if (FIELD_GET(MLXBF_DIMM_INFO__IS_RDIMM, smc_info))
+                       dimm->mtype = MEM_RDDR4;
+               else
+                       dimm->mtype = MEM_DDR4;
+
+               dimm->nr_pages =
+                       FIELD_GET(MLXBF_DIMM_INFO__SIZE_GB, smc_info) *
+                       (SZ_1G / PAGE_SIZE);
+               dimm->grain = MLXBF_EDAC_ERROR_GRAIN;
+
+               /* Mem controller for BlueField only supports x4, x8 and x16 */
+               switch (FIELD_GET(MLXBF_DIMM_INFO__PACKAGE_X, smc_info)) {
+               case 4:
+                       dimm->dtype = DEV_X4;
+                       break;
+               case 8:
+                       dimm->dtype = DEV_X8;
+                       break;
+               case 16:
+                       dimm->dtype = DEV_X16;
+                       break;
+               default:
+                       dimm->dtype = DEV_UNKNOWN;
+               }
+
+               priv->dimm_ranks[i] =
+                       FIELD_GET(MLXBF_DIMM_INFO__RANKS, smc_info);
+       }
+
+       if (is_empty)
+               mci->edac_cap = EDAC_FLAG_NONE;
+       else
+               mci->edac_cap = EDAC_FLAG_SECDED;
+}
+
+static int bluefield_edac_mc_probe(struct platform_device *pdev)
+{
+       struct bluefield_edac_priv *priv;
+       struct device *dev = &pdev->dev;
+       struct edac_mc_layer layers[1];
+       struct mem_ctl_info *mci;
+       struct resource *emi_res;
+       unsigned int mc_idx, dimm_count;
+       int rc, ret;
+
+       /* Read the MSS (Memory SubSystem) index from ACPI table. */
+       if (device_property_read_u32(dev, "mss_number", &mc_idx)) {
+               dev_warn(dev, "bf_edac: MSS number unknown\n");
+               return -EINVAL;
+       }
+
+       /* Read the DIMMs per MC from ACPI table. */
+       if (device_property_read_u32(dev, "dimm_per_mc", &dimm_count)) {
+               dev_warn(dev, "bf_edac: DIMMs per MC unknown\n");
+               return -EINVAL;
+       }
+
+       if (dimm_count > MLXBF_EDAC_MAX_DIMM_PER_MC) {
+               dev_warn(dev, "bf_edac: DIMMs per MC not valid\n");
+               return -EINVAL;
+       }
+
+       emi_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!emi_res)
+               return -EINVAL;
+
+       layers[0].type = EDAC_MC_LAYER_SLOT;
+       layers[0].size = dimm_count;
+       layers[0].is_virt_csrow = true;
+
+       mci = edac_mc_alloc(mc_idx, ARRAY_SIZE(layers), layers, sizeof(*priv));
+       if (!mci)
+               return -ENOMEM;
+
+       priv = mci->pvt_info;
+
+       priv->dimm_per_mc = dimm_count;
+       priv->emi_base = devm_ioremap_resource(dev, emi_res);
+       if (IS_ERR(priv->emi_base)) {
+               dev_err(dev, "failed to map EMI IO resource\n");
+               ret = PTR_ERR(priv->emi_base);
+               goto err;
+       }
+
+       mci->pdev = dev;
+       mci->mtype_cap = MEM_FLAG_DDR4 | MEM_FLAG_RDDR4 |
+                        MEM_FLAG_LRDDR4 | MEM_FLAG_NVDIMM;
+       mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+
+       mci->mod_name = DRIVER_NAME;
+       mci->ctl_name = "BlueField_Memory_Controller";
+       mci->dev_name = dev_name(dev);
+       mci->edac_check = bluefield_edac_check;
+
+       /* Initialize mci with the actual populated DIMM information. */
+       bluefield_edac_init_dimms(mci);
+
+       platform_set_drvdata(pdev, mci);
+
+       /* Register with EDAC core */
+       rc = edac_mc_add_mc(mci);
+       if (rc) {
+               dev_err(dev, "failed to register with EDAC core\n");
+               ret = rc;
+               goto err;
+       }
+
+       /* Only POLL mode supported so far. */
+       edac_op_state = EDAC_OPSTATE_POLL;
+
+       return 0;
+
+err:
+       edac_mc_free(mci);
+
+       return ret;
+
+}
+
+static int bluefield_edac_mc_remove(struct platform_device *pdev)
+{
+       struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+       edac_mc_del_mc(&pdev->dev);
+       edac_mc_free(mci);
+
+       return 0;
+}
+
+static const struct acpi_device_id bluefield_mc_acpi_ids[] = {
+       {"MLNXBF08", 0},
+       {}
+};
+
+MODULE_DEVICE_TABLE(acpi, bluefield_mc_acpi_ids);
+
+static struct platform_driver bluefield_edac_mc_driver = {
+       .driver = {
+               .name = DRIVER_NAME,
+               .acpi_match_table = bluefield_mc_acpi_ids,
+       },
+       .probe = bluefield_edac_mc_probe,
+       .remove = bluefield_edac_mc_remove,
+};
+
+module_platform_driver(bluefield_edac_mc_driver);
+
+MODULE_DESCRIPTION("Mellanox BlueField memory edac driver");
+MODULE_AUTHOR("Mellanox Technologies");
+MODULE_LICENSE("GPL v2");